美国电话电报美股招股说明书(2026-04-27版)

Prospectus SupplementApril23, 2026(To Prospectus dated February28, 2025) AT&T INC. U.S.$750,000,000 4.750% Global Notes due 2033U.S.$1,750,000,000 5.250% Global Notes due 2036U.S.$500,000,000 5.850% Global Notes due 2046U.S.$2,000,000,000 6.200% Global Notes due 2056U.S.$1,000,000,000 6.300% Global Notes due 2066 We will pay interest on the 4.750% Global Notes due 2033 (the “2033 Notes”) on April30 and October30 of each year, commencing on October30, 2026, the5.250% Global Notes due 2036 (the “2036 Notes”) on April30 and October30 of each year, commencing on October30, 2026, the 5.850% Global Notes due 2046 (the“2046 Notes”) on April30 and October30 of each year, commencing on October30, 2026, the 6.200% Global Notes due 2056 (the “2056 Notes”) on April30 andOctober30 of each year, commencing on October30, 2026 and the 6.300% Global Notes due 2066 (the “2066 Notes” and, together with the 2033 Notes, the 2036 Notes,the 2046 Notes and the 2056 Notes, the “Notes”), on April30 and October30 of each year, commencing on October30, 2026. The 2033 Notes will mature on April30,2033, the 2036 Notes will mature on October30, 2036, the 2046 Notes will mature on April30, 2046, the 2056 Notes will mature on October30, 2056 and the 2066Notes will mature on October30, 2066. The 2033 Notes constitute a further issuance of, and will form a single series with, the U.S.$1,250,000,000 4.750% Global Notesdue 2033 issued on February5, 2026. The 2046 Notes constitute a further issuance of, and will form a single series with, the U.S.$850,000,000 5.850% Global Notes due2046 issued on February5, 2026. We may redeem some or all of the Notes at any time and from time to time at the prices and at the times indicated under the heading “Description of the Notes—Optional Redemption” beginning on page S-5 of this prospectus supplement. The Notes will be issued in minimum denominations of $2,000 and integral multiples of$1,000 thereafter. See “Risk Factors” beginning on page 7 of our Annual Report on Form 10-K for the fiscal year ended December31, 2025, whichare incorporated by reference herein, to read about factors you should consider before investing in the Notes. Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon theaccuracy or adequacy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. The initial public offering prices set forth above do not include accrued interest, if any. Interest on the 2033 Notes and the 2046 Notes will accrue from February5,2026, and interest on the 2036 Notes, the 2056 Notes and the 2066 Notes will accrue from April30, 2026. The underwriters expect to deliver the Notes in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants,including Clearstream Banking S.A. and Euroclear Bank SA/NV, against payment in New York, New York on April30, 2026. Table of Contents We have not, and the underwriters have not, authorized any other person to provide you with different information. If anyone providesyou with different or inconsistent information, we take no responsibility for, nor can we provide any assurance as to the reliability of, any otherinformation that others may give you. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdictionwhere the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement and theaccompanying prospectus, as well as information we previously filed with the Securities and Exchange Commission and incorporated byreference, is accurate as of their respective dates. Our business, financial condition, results of operations and prospects may have changed sincethose dates. The Notes are offered globally for sale in those jurisdictions in the United States, Canada, Europe, Asia and elsewhere where it is lawful tomake such offers. Prohibition of sales to EEA retail investors—The Notes are not intended to be offered, sold or otherwise made available to and should not beoffered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”). For these purposes, a retail investor means aperson who is one (or more) of: (i)a retail client as defined in point (11)of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); (ii) acustomer within the meaning of Directive (EU) 2016/97 (as amended, the “Insurance Distribution Directive”), where that customer would not qualify asa professional client as defined in point (10)of Article 4(1) of MiFID II; or (iii)not a qualified investor as defined in Regulation (EU) 2017/1129 (asamended, the “Prospectus Regulation”). Consequently, no key information document required by Regulation (EU) No 1286/2014 (as amended, the“PRIIPs Regulation”) for offering or selling the Notes or otherwise making them available to reta